摘要
为了获取6~35 kV中压电网暂态过电压的实际波形数据,设计了基于2级分压的过电压在线监测装置。该装置采用2级分压器作为电压传感器,其中第1级分压器采用分压比为1 000：1的低阻尼阻容串联分压,第2级分压器采用分压比为15：1的阻容串联分压,2者通过同轴电缆构成首末端匹配。通过在2级分压器的入口和出口分别加装瞬态电压抑制器可提高装置的安全性。通过电路理论和方波响应试验分析了分压器的设计原理和响应特性,通过增加接地线的表面积解决了在冲击高压下出现的波形振荡问题。通过硬件电路产生下降沿触发信号,利用软件判断下降沿达到触发水平时触发数据采集卡,极大地提高了触发可靠性。工频试验和标准雷电冲击试验表明,三相分压器的工频分压比和冲击分压比的最大误差小于6%;触发电压设置为54 kV,当过电压幅值超过触发阈值时,能够准确记录过电压波形,并且触发可靠。通过有无避雷器并联时的冲击电压试验表明,该装置能承受幅值为127.5 kV的负极性冲击过电压,无电磁兼容问题,并能够采集避雷器动作后的暂态过电压。
To obtain the actual transient overvoltage waveforms in 6-35 kV medium voltage grid, an on-line monitoring device based on two-stage subdivision for overvoltages is designed. The device uses a two-stage divider as a voltage sen- sor. The first stage divider is a low damping resistor-capacitor divider and its ratio is 1 000：1, the second stage divider is a resistor-capacitor divider and its ratio is 15：1, and the two dividers are matched through coaxial cable. Through installing TVS respectively in the two-stage dividers, the safety of the device is improved. Meanwhile, the divider＇s designing Prin- ciples and response characteristics are analyzed through circuit principle and the square wave response, and the oscillation waveforms during debugging are weakened through increasing ground wire area. A falling trigger signal is generated by a hardware circuit and the trigger level is determined by software to trigger data acquisition card, which greatly improves the reliability of the trigger. The power frequency and standard lightning impulse test show that the maximum error of the impulse voltage ratio and the power frequency voltage ratio of the three dividers is less than 6%; the trigger voltage is set to 54 kV, which can record the overvoltage waveforms when the amplitude exceeds the threshold value, and the trigger is reliable. The impulse voltage test in the presence and absence of the parallel of the lighting arrester, respectively, shows that the device can withstand the negative impulse voltage of the amplitude of 127.5 kV and has good electromagnetic compatibility, and can capture the transient overvoltage after the action of the lighting arrester.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2015年第11期3583-3589,共7页
High Voltage Engineering
基金
中国博士后科学基金(2015T80976)~~
关键词
阻容串联分压器
过电压在线监测
电压传感器
两级分压
数据采集卡
冲击电压
触发可靠性
series resistance capacity voltage divider
overvoltage online monitoring
voltage sensor
two-stage subdivision
data acquisition card
impulse voltage
trigger reliability
